Apple CEO Tim Cook recently gave a powerful speech at a privacy conference in Brussels. He spoke about the wonders of technology. But his main focus was on the grave dangers with which mankind has been suddenly confronted.

“Platforms and algorithms that promised to improve our lives can actually magnify our worst human tendencies,” Cook stated. “Rogue actors and even governments have taken advantage of user trust to deepen divisions, incite violence, and even undermine our shared sense of what is true and what is false.”

Cook summed up the most frightening truth about technology today–in a single powerful sentence:

“Our own information, from the everyday to the deeply personal, is being weaponized against us with military efficiency.”

Let’s consider those words for a moment.

A weapon of mass persuasion

Technology has unleashed some truly deadly weapons through the years. Automatic firearms, along with chemical and nuclear weapons, have been used to cause countless deaths over the past century. 

But Cook highlights a far more dangerous weapon–one that uses knowledge about you: your thoughts, your feelings, your emotions. 

Cook explained further in his speech:

Every day, billions of dollars change hands and countless decisions are made on the basis of our likes and dislikes, our friends and families, our relationships and conversations, our wishes and fears, our hopes and dreams. 

These scraps of data, each one harmless enough on its own, are carefully assembled, synthesized, traded, and sold.

Taken to its extreme, this process creates an enduring digital profile and lets companies know you better than you may know yourself. Your profile is then run through algorithms that can serve up increasingly extreme content, pounding our harmless preferences into hardened convictions.

It is this “enduring digital profile” that can be used against you, in an effort to persuade, influence, and manipulate, completely without your knowledge.

I write in detail about this insidious danger in my recently published book, EQ Applied: The Real World Guide to Emotional Intelligence.This invaluable data is being used to feed what we describe as “the dark side” of emotional intelligence–when persons or organizations use knowledge of a person’s thoughts and emotions to strategically achieve self-serving goals.

Companies use this data in a variety of underhanded ways, ranging from their attempts to sell products targeted to your individual tastes, preferences, and circumstances (while hiding how much they actually know about you) to selling your harvested data and that of millions of others in an attempt toinfluence the political landscape.

“We shouldn’t sugarcoat the consequences,” Cook said in his speech. “This is surveillance. And these stockpiles of personal data serve only to enrich the companies that collect them.”

So, how can you protect yourself in this battle for your mind?

First of all, it’s important to realize that social media apps and websites are powerful and potentially dangerous tools. Just like a sharp knife can be used either to prepare food or to cause injury, social media can be used to help you or to harm you.

Recognizing the power such platforms have to provide insights into your behavior, you may decide to do the following:

1. Limit the access websites have to your personal data. 

Remember that you have control over what data you share with websites and social media. Utilize private browsing and privacy controls to do so. 

If the website or app you’re attempting to use makes this difficult, ditch it. 

2. Use the 3-Question Rule.

You may be completely willing to share your thoughts or opinions online. But if you do, remember that there are people who will use those thoughts and opinions in an effort to manipulate you. 

So, before posting anything, ask yourself three questions:

  • Does this need to be said?
  • Does this need to be said by me?
  • Does this need to be said by me, now?

If the answer to any of these questions is no, think twice before posting.

3. Work to increase your self- and social awareness.

Both self-awareness (the ability to identify and understand your own emotions and how they affect you) and social awareness (your capacity to accurately perceive others’ abilities to manage emotions) can serve as valuable self-defense mechanisms.

Such “emotional alarm systems” can help alert you to the fact that someone is attempting to manipulate your feelings, to get you to act in a way that is not in your best interests or that conflicts with your values and principles. 

At some point, you will cross paths with those who attempt to use your data against you.

In fact, you probably already have. 

“This crisis is real,” Cook went on to say. “It is not imagined or exaggerated or ‘crazy.’ And those of us who believe in technology’s potential for good must not shrink from this moment.”

Enjoy this post? Check out my book, EQ Applied, which uses fascinating research and compelling stories to illustrate what emotional intelligence looks like in everyday life.

A version of this article originally appeared on Inc.com.